She was standing on a nearby overpass and was actually able to see her husband, Paul, down on the highway and wave to him.

"He was in a standstill, there was an accident before. The road was stopped and he came up to the stop and he heard a Suburban coming up from behind him. He said he couldn't apply the brakes anymore and he smacked into everybody else. Paul had said once he hit him he felt his car spinning and sideswiped other cars and his windows blew out."

People were seen getting out of and walking between the vehicles all along the closed stretch of highway.

"My car began spinning and then the FedEx truck slid into my car," said Tracey Wood, who was a passenger in the minivan driven by her husband, Jeff Wood.

"What saved me was the tractor trailer and the FedEx truck," Wood said. "The FedEx truck kind of blocked me from getting hit," she said live on 6abc.

"I looked over and said to Tracey, 'I think cars are spinning out in front of us,'" said Jeff Wood. "So I went to hit my brakes to stop and tried to avoid cars and before you know it we just started spinning."

Another witness, Kristen Good, also called in to Action News. She described the moments after the crash.

"I called my husband right away, saying 'You're not going to believe this," she said. "I said there were about 20 accidents behind me."

Abington Hospital said 16 injured people were taken there but, by 5 p.m., 15 of those people had gone home.

Other injured patients were taken to various local hospitals, including St. Mary Medical Center and Doylestown Hospital.

Volunteers from The American Red Cross of Southeastern Pennsylvania and the Salvation Army headed to the scene to bring food, water and blankets to stranded motorists.

The cause of the initial crash is still under investigation.

It is possible that heavy winds, drifting snow, and patches of ice on the roadway, along with some drivers traveling too fast for conditions contributed to the cause of the crash.